Reducing the power loss in electric loads has been a focus of much development for some time. While early work focused on power transmission losses, more recent developments have also addressed power losses in 220 volt and 110 volt residential and commercial site load networks. Power efficiency meters connected between a utility metering device and a residential or commercial load have measured the power loss or efficiency of such a site load network.
It has been found that power loss can be reduced by altering the sinusoidal shape of the 60 cycle voltage supplied by a utility company. The object of such previous work was to reduce the transition time of the voltage from half peak value to half peak value. This has been done with 110 volt or 220 volt power supplies connected between a utility metering device and an electrical load.
A power supply having an internal dc battery is disclosed in U.S. Pat. No. 3,319,074, wherein an external ac source is rectified and applied to a load under control of a transistor. The dc battery compensates for any fluctuations of the ac power source and is maintained in a fully charged condition. The operation of this power supply, while designed to maintain a constant voltage on the load, introduces additional power losses and does not cope with the varying demands of ac loads, insofar as efficient supply of energy is concerned.
U.S. Pat. No. 4,206,367 (Petruska, et al.), shows a 220 volt power supply having an internal dc battery and a charge/discharge circuit. This device operates to reduce the power drawn from the utility company supplied external ac source while servicing the residential load.
Use of the power supply shown in U.S. Pat. No. 4,206,367, in cooperation with electrical loads, has resulted in the increased use of power consumption metering of the power supplied by public utilities to their customers. These power use meters presently are unable to accurately measure energy savings actually being attained.
A residential use or power consumption meter is connected directly to the utility power metering device and uses the 220 volt power supplied at that point to calculate and record (by magnetic rotating dial and hand pointers) the power consumption of the customer. Residential use, while sometimes at 220 volts; e.g. electric ranges and clothes dryers, is primarily delivered at 110 volts. This is accomplished by splitting the three-wire 220 volt supply line into two, two-wire 110 volt subcircuits in the residential distribution box; i.e., the circuit breaker box.
The power supply of the Petruska patent is a 220 volt device which is intended to be connected between the utility power metering device and the residential circuit breaker box. The power consumption meter is a 220 volt device which is intended to be connected between the utility power metering device and the power supply of the Petruska patent. Because the power consumption meter measures 220 volt current usage across the load to calculate residential power consumption at both 220 volts and 110 volts, an error in calculating the true power consumption can occur.
An object of the present invention is to provide an electrical power consumption error correction circuit means for a 220 volt ac power consumption meter.
A further object of the present invention is to incorporate such an electrical power consumption error correction circuit means into a residential power supply of the type shown in U.S. Pat. No. 4,206,367.
An additional object of the present invention to provide a residential power supply with an electrical power consumption error correction circuit means which reduces 220 volt drawdown from the utility company ac voltage supply during 110 volt load usage.